CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Consolidated revenue	$ 591.9	$ 600.1	$ 1,135.1	$ 1,212.6
Consolidated expenses:
Compensation and related expenses	258.0	241.0	486.2	507.7
Selling, general and administrative	96.2	105.2	191.8	211.6
Intangible amortization and impairments	21.2	23.2	50.9	46.4
Interest expense	19.7	21.4	37.9	43.0
Depreciation and other amortization	5.3	5.7	10.6	11.2
Other expenses (net)	12.2	11.1	23.0	23.2
Total consolidated expenses	412.6	407.6	800.4	843.1
Equity method income (loss) (net)	29.4	35.3	(328.8)	131.6
Investment and other income	7.2	11.5	15.2	25.7
Income before income taxes	215.9	239.3	21.1	526.8
Income tax expense (benefit)	35.7	34.1	(26.1)	97.5
Net income	180.2	205.2	47.2	429.3
Net income (non-controlling interests)	(72.5)	(88.2)	(140.3)	(159.3)
Net income (loss) (controlling interest)	$ 107.7	$ 117.0	$ (93.1)	$ 270.0
Average shares outstanding (basic) (in shares)	51.0	54.0	51.5	54.3
Average shares outstanding (diluted) (in shares)	51.0	54.2	51.5	56.8
Earnings (loss) per share (basic) (in dollars per share)	$ 2.11	$ 2.17	$ (1.81)	$ 4.97
Earnings (loss) per share (diluted) (in dollars per share)	$ 2.11	$ 2.16	$ (1.81)	$ 4.92

The aggregate expense charged against earnings to allocate the cost of tangible assets to periods in which the assets are used and held and to allocate the cost of issuing debt to periods in which the debt is outstanding. As a noncash expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method.

No definition available.